string t_s(int n){
    int m = n;
    char s[105];
    char ss[105];
    int i=0,j=0;
    if (n < 0){
        m = 0 - m;
        j = 1;
         ss[0] = '-';
    }    
    else if(n==0){
    	return "0";
	}
    while (m>0){
        s[i++] = m % 10 + '0';
        m /= 10;
    }
    s[i] = '\0';
    i=i-1;
    while(i >= 0){
        ss[j++] = s[i--];
    }    
    ss[j] = '\0'; 
    return ss;
}
